[travis] Disable download jobs

Until youtube-dl OSS approval by Travis or moving to GitHub Actions
[ci skip]

.travis.yml

@@ -12,29 +12,29 @@ python:
 dist: trusty
 env:
   - YTDL_TEST_SET=core
-  - YTDL_TEST_SET=download
+#  - YTDL_TEST_SET=download
 jobs:
   include:
     - python: 3.7
       dist: xenial
       env: YTDL_TEST_SET=core
-    - python: 3.7
-      dist: xenial
-      env: YTDL_TEST_SET=download
+#    - python: 3.7
+#      dist: xenial
+#      env: YTDL_TEST_SET=download
     - python: 3.8
       dist: xenial
       env: YTDL_TEST_SET=core
-    - python: 3.8
-      dist: xenial
-      env: YTDL_TEST_SET=download
+#    - python: 3.8
+#      dist: xenial
+#      env: YTDL_TEST_SET=download
     - python: 3.8-dev
       dist: xenial
       env: YTDL_TEST_SET=core
-    - python: 3.8-dev
-      dist: xenial
-      env: YTDL_TEST_SET=download
+#    - python: 3.8-dev
+#      dist: xenial
+#      env: YTDL_TEST_SET=download
     - env: JYTHON=true; YTDL_TEST_SET=core
-    - env: JYTHON=true; YTDL_TEST_SET=download
+#    - env: JYTHON=true; YTDL_TEST_SET=download
     - name: flake8
       python: 3.8
       dist: xenial
@@ -42,9 +42,9 @@ jobs:
       script: flake8 .
   fast_finish: true
   allow_failures:
-    - env: YTDL_TEST_SET=download
+#    - env: YTDL_TEST_SET=download
     - env: JYTHON=true; YTDL_TEST_SET=core
-    - env: JYTHON=true; YTDL_TEST_SET=download
+#    - env: JYTHON=true; YTDL_TEST_SET=download
 before_install:
   - if [ "$JYTHON" == "true" ]; then ./devscripts/install_jython.sh; export PATH="$HOME/jython/bin:$PATH"; fi
 script: ./devscripts/run_tests.sh